Referring to FIGS. 1 through 4, a typical conventional water shut-off diaphragm pump 1 currently used in reverse osmosis water purification system comprises a motor 10 with a plurality of screw bores 12 configured on the peripheral thereof, a motor upper hood chassis 11 with a motor output shaft (not shown in figures), three pumping pistons 13 driven by the motor output shaft to axially move for reciprocally pumping function, a valvular diaphragm cover assembly 20 and a pump cover body 30 with a plurality of perforated bore 37 configured on the peripheral thereof in corresponding with the screw bores 12 on the motor 10; by driving bolts 2 through screw bores 12 on the motor 10 and corresponding perforated bore 37 on the pump cover body 30, the motor 10, the valvular diaphragm cover assembly 20 and the pump cover body 30 can be securely combined into an integral body (as shown in FIG. 2), wherein:
Said valvular diaphragm cover assembly 20 includes an upper valvular cover 21 stacked on a diaphragm 22, a high pressure anti-backflow valve 23 inset in the center of the upper valvular cover 21, three low pressure anti-backflow valves 24 disposed around the peripheral of the high pressure anti-backflow valve 23 in radial manner of evenly sector space and three preliminary low pressure water chambers 25 such that each low pressure water chamber 25 is interposed between each pair of adjacent low pressure anti-backflow valves 24 (as shown in FIGS. 1 and 4);
Said pump cover body 30, which is a hollow body having downward opening with an internal tiered rim 33 encompassing a nested annular well wall 34 in concentric manner, includes a containing pit 301 outwardly configured on the top thereof, an inlet port 31, an outlet port 32 respectively disposed in the peripheral thereof in mutually opposed manner such that both inlet port 31 and outlet port 32 are orthogonal to the containing pit 301 (as shown in FIG. 3) as well as an intensively high-pressured water chamber 35 is created between the internal wall of the annular well wall 34 and top surface of the upper valvular cover 21 when the pump cover body 30 securely docks with the valvular diaphragm cover assembly 20; at this moment, both peripherals of the upper valvular cover 21 and diaphragm 22 as well as the peripheral of the high pressure anti-backflow valve 23 on the valvular diaphragm cover assembly 20 will hermetically attach with each terminal ring of the tiered rim 33 and annular well wall 34 respectively (as shown in FIG. 4); Wherein, a central vertical top opening flow directing compartment 302 with a horizontal outlet passage 36 connecting with the outlet port 32, a vertical annular tunnel 303 and a water passage 304 are created at the lower section of said containing pit 301 so that the high-pressured water chamber 35 and containing pit 301 can be communicable via annular tunnel 303 while the inlet port 31 and containing pit 301 can be communicable via water passage 304 because the annular tunnel 303 encompasses the flow directing compartment 302 with a separating cylinder interposed between them while the water passage 304 externally leads the annular tunnel 303 with a separating cylinder interposed between them (as shown in FIGS. 3 and 4);
From bottom to top orderly imbedded in said pump cover body 30 are a planiform plastic elastic membrane baffle disk 40, an obstructing ring 50 with an annular dent 51 on top surface thereof, a compressed spring 3 and a hood cover mount 60, whose lower section is disposed a downward annular well wall 61 with a plurality of radial flow directing bores 62 created thereon (as shown in FIG. 3), wherein the outer diameter of the obstructing baffle 50 is slightly smaller than inner diameter of the annular well wall 61 so that the obstructing baffle 50 can be inset into the annular well wall 61 of the hood cover mount 60. The assembling steps are as following: firstly, put the elastic membrane baffle disk 40 on the flow directing compartment 302 of the containing pit 301, then attach the obstructing baffle 50 over the elastic membrane baffle disk 40; secondly, put one end of the compressed spring 3 against the annular dent 51 of the obstructing baffle 50, and finally, dock the hood cover mount 60 with the containing pit 301, and then securely fix them by screws. Thereby, the sole surface of the elastic membrane baffle disk 40 can simultaneously block the top openings of the flow directing compartment 302, annular tunnel 303 and water passage 304 by means of stretching force of the compressed spring 3 pushed the annular well wall 61 of the hood cover mount 60 against the elastic membrane baffle disk 40 (as shown in FIG. 4).
Further referring to FIGS. 5 through 7, the operation for the conventional water shut-off diaphragm pump is described as below. Firstly, when the motor 10 is turned on, the tap water W is alternately pumped into three low pressure water chambers 25 orderly via the inlet port 31 of the pump cover body 30 and three low pressure anti-backflow valves 24 by three pumping pistons 13 in axially move for reciprocally pumping function driven by the motor 10 so that the tap water W is preliminarily squeezed into pressurized water Wp of 60 psi˜120 psi water pressure in the low pressure water chambers 25 (as indicated by hollow arrowhead shown in FIG. 5); Secondly, the pressurized water Wp of 60 psi˜120 psi water pressure is further alternately pumped into the high-pressured water chamber 35 orderly via three sectors of high pressure anti-backflow valve 23 so that the pressurized water Wp of 60 psi˜120 psi water pressure is intensively compressed into pressurized water Wp of higher water pressure in the high-pressured water chamber 35; Thirdly, the high pressurized water Wp in the high-pressured water chamber 35 is further pumped into the flow directing compartment 302 orderly via the annular tunnel 303 and elastic membrane baffle disk 40, which is now driven to open by the high pressurized water Wp; and Finally, the high pressurized water Wp in the flow directing compartment 302 is further impelled to discharged out of the water shut-off diaphragm pump 1 orderly via the outlet passage 36 and the outlet port 32 of the pump cover body 30 (as indicated by solid arrowhead shown in FIG. 5) to serve as a supply pressurized water of rated water pressure for being filtered in the RO filter core membrane cartridge of subsequent reverse osmosis purification system.
Further referring to FIG. 7, the shutdown procedure for the conventional water shut-off diaphragm pump is described as below. Firstly, when the motor 10 is turned off, some residual pressurized water Wp in previous operation will be remained in the high-pressured water chamber 35 while the tap water W is driven into the containing pit 301 orderly via the inlet port 31 and water passage 304 of the pump cover body 30 (as indicated by hollow arrowhead shown in FIG. 7); Secondly, the tap water W in the containing pit 301 is further driven into hollow space encompassed by the annular well wall 61 via the flow directing bores 62 of the annular well wall 61 in the hood cover mount 60; and Finally, the combined downward force by the water pressure of the tap water W in the hollow space encompassed by the annular well wall 61 and the resilient force of the compressed spring 3 will push the obstructing ring 50 and elastic membrane baffle disk 40 downwardly to block the annular tunnel 303 because the combined downward force is greater than the upward water pressure of the residual pressurized water Wp remained in the high-pressured water chamber 35. Thus, the residual pressurized water Wp remained in the high-pressured water chamber 35 is blocked and disabled to flow into the flow directing compartment 302 (as shown in FIG. 7) for being discharged out of the water shut-off diaphragm pump 1 to serve as a supply pressurized water in the subsequent reverse osmosis purification system so that the automatically water shut-off function is achieved.
Further referring to FIGS. 5 and 6, the drawback in the operation for the conventional water shut-off diaphragm pump is described as below. As described in foregoing normal operation, the tap water W is firstly pumped by three pumping pistons 13, which is driven by the motor 10, into the low pressure water chambers 25 to become high pressurized water Wp, which is further pumped into the flow directing compartment 302 orderly via the annular tunnel 303 and elastic membrane baffle disk 40 from the high-pressured water chambers 35. Suppose the motor 10 rotates in 700 revolutions per minute (700 RPM), 2100 times per minute of high pressurized water Wp will be pumped into the flow directing compartment 302 since each of three pumping pistons 13 is alternately driven one time by each revolution of the motor 10. Consequently, the momentum frequency of the high pressurized water Wp in the flow directing compartment 302 will be 2100 times per minute before the high pressurized water Wp flows to the outlet passage 36 (as shown in FIG. 5). Wherein, the impacting direction from the momentum of the high pressurized water Wp to the surrounding internal wall of the flow directing compartment 302 is in random manner (as indicated by enlarged view shown in FIG. 6). Thereby, under such high frequency of the momentum by the high pressurized water Wp, vibration of the pump cover body 30 with annoying noise is created. Once the water shut-off diaphragm pump 1 is powered on to operate for being used in subsequent reverse osmosis purification system, the user must be suffered from such annoying noise thereof. Chronically, the annoying noise not only disturbs the peaceful household environment but also jeopardizes to the human health. Therefore, how to effectively delete the annoying noise becomes a critical issue for the manufacturers of the water shut-off diaphragm pump. However, no effective and simple solution is worked out up to now.